Brake shoe gauge



y 1937' L. B BLACKMAN 2,

BRAKE-SHOE GAUGE Filed Dec. 50, 1935 INVENTOR.

I/Q/M /QZQZME 221 ATTORNEY Patented July 20, 1937 UNITED STATES PATENT OFFICE 5 Claims.

My invention relates to improvements in brake shoe gauges. It is particularly well adapted for adjusting internal expanding brake shoes centrally and for proper clearance.

One of the objects of my invention is to provide a novel gauge which is adapted for operatively mounting on both the cylindrical and tapered portions of an axle spindle.

A further object of my invention is the provision of a gauge of novel structure which is provided with means for quickly and correctly adjusting for proper clearance.

Still another object of my invention is the provision of novel means for visually designating clearance values.

Another object of my invention is the provision of a gauge of the kind described which is simple, cheap, easily and quickly applied to its operative position, which is strong, durable, not likely to get out of order and which is efiicient in its operation.

The novel features of my invention are hereinafter fully described and claimed.

In the accompanying drawing which illustrates the preferred embodiment of my invention,

Fig. 1 is a front elevation of my improved gauge shown mounted in operative position on a brake structure of the internal expanding type, an end portion of the front axle being shown.

Fig. 2 is a sectional view on the line 22 of Fig. 1, the brake parts being shown in oblique section, the axle being shown in side elevation, the gauge being mounted on the cylindrical part.

Fig. 3 is a view partly in elevation and partly in vertical section of my improved gauge shown mounted on the tapered portion of the spindle and operatively engaging the brake shoe, a portion of which is shown in vertical section, part of the rear axle and rear axle housing being shown.

Fig. 4 is an enlarged section on the line 4-4 of Fig. 3.

Fig, 5 is a top view of the gauge.

. Fig. 6 is a cross section on the line 6-6 of Fig. 4, looking upward, and partly broken away.

Fig. '7 is a section on the line 6-6 looking downward and partly broken away.

Fig. 8 is an enlarged section on the line 8-8 of Fig. 5.

Fig. 9 is a reduced sectional view on the line 99 of Fi 5.

Fig. 10 is an enlarged view, partly in side elevation and partly in section of the clamping screw in the yoke, partly broken away.

Fig. 11 is a side elevation of the'centralizing and clearance disk, enlarged.

Fig. 12 is an enlarged front elevation of the pivotally adjustable block and parts connected therewith.

Similar characters of reference designate similar parts in the different views.

I designates each of two expanding brake shoes of usual type, respectively pivoted by means of two fulcra 2 which are inwardly and outwardly adjustable. 3 designates two adjusting eccentrics with which the brake shoes I are adjusted in a well known manner. 4 designates the lining on the periphery of each brake shoe I adapted to bear against the inner periphery of the usual brake drum, not shown.

5 designates a plate on which are mounted the brake shoes I of one of the front brakes, which plate also carries the adjacent eccentrics 3 and fulcra 2.

6 designates the front axle spindle, I the rear axle spindle and 8 part of the axle housing which carries the rear brake eccentrics 3 and fulcra 2.

My improved gauge comprises a centralizing and clearance determining member, which in its preferred form consists of a disk 9, the periphery of which is adapted to contact with the outer side of the brake lining 4, a tubular screw III which extends through a hole disposed eccentrically through the disk 9, and a nut I I, mounted on the screw I0 and holding the disk 9 clamped against the head of the screw III, as shown in Fig. 8.

Supporting means on which the screw III and disk 9 are revoluble comprises the following described parts.

A screw I2 has its threaded end mounted in one end of a rod I3, the other end of the screw has a cylindrical extension I4 on which the screw II! is revoluble. The outer end of the extension I4 has a threaded longitudinal hole in which is fitted a screw I5 on which is mounted a washer I6 which holds the screw II] fro-m coming off from that end of the extension I4.

The rod I3 is longitudinally adjustable in and extends through a hole in a block I! which is pivotally mounted on an axis at right angles to the rod I3 and which comprises a screw I8 mounted in a threaded hole in a block I9.

For holding the block H in the position to which it may be pivotally adjusted on the block I9, a clamping screw 20 extends through an arcuate slot 2I in the block I1, and has its inner endfitted in a threaded hole in the block I9. By swinging the block I! on the screw I 8, the rod I3 may be tiltably adjusted. A set screw 22 mounted in a threaded hole in the block II bears on the rod [3 and holds it in the position to which it may be adjusted in the block [1. By tightening the screw 20 against the block I! after it has been pivotally adjusted on the block l9, the block ll is held in its adjusted position.

The block 53 is radially adjustable on a radial rod 23, the lower end of which is fastened rigidly in a radial hole in an annular yoke 24 adapted to encircle a front axle 6 or a rear axle l. A set screw 25 is fitted in a threaded hole in the block is and is adapted to have its inner end bear against the rod 23 to hold the block H3 in its adjusted position on the rod 23.

Fitted in a threaded hole parallel with the rod 23 in the block i9 is a screw 23 the lower end of which is adapted to enter a recess 21 in the upper side of a block 28 also radially adjustable on the rod 23 to whichit is secured in its adjusted position by a set screw 29 fitted in a threaded hole in the block 28 and adapted to bear against the rod 23.

A pin 3&3 which is parallel with the rod 23 is mounted in a hole in the block 28 and is slidably fitted in a hole 3! in the block i9, Fig. 9. This pin holds the blocks i9 and 28 from relative turning on the rod 23. Aline-d with the rod 23 is a screw 32 which is fitted in a threaded hole extending through the yoke 24 diametrically opposite the rod 23. The inner end of the screw 32 has a recess 33 in which is held a revoluble ball 34, Fig. 10. This ball is adapted to bear on the periphery of the cylindrical part or the tapering part of the axle spindle on which the yoke is to be mounted.

Opposite the screw 32 the yoke 24 is provided on its inner side with a V shaped portion 35 adapted to bear against an axle spindle on the side opposite that against which bears the ball 34. a

The yoke 24 at one side of the rod 23 is provided with a threaded hole. in which is fitted an adjusting screw 36 adapted to bear against the spindle on which the yoke 24 is mounted.

When the yoke is mounted on the tapered part of a spindle, as on the rear axle spindle 1, Fig. 3, the adjusting screw 36 is turned so as to. tilt the yoke 24 and with it the rod 23 to a substantially upright position. The screws 3632 are then tightened, so that the gauge may be revolved bodily by revolving the spindle 1, for reasons hereinafter explained.

When the yoke 24 is mounted revolubly on the cylindrical part of a spindle, as on the spindleE in Fig. 2, the screw 35 need not be employed to hold the yoke, but the screw 32 is adjusted so that the ball 34 bears firmly against the spindle.

The yoke 24, screw 32 and rod 23 serve as a support for the supporting means of the centralizing and clearance determining disk 9, comprising the blocks 28, I9 and I1, rod I 3 and associated parts.

The disk 9 is provided with cooperating means for determining clearance values comprising spaced apart radial lines 31 provided on one side of the disk 9. Respectively adjacent to said radial lines 37 are numerals as 0, 5, 10, 15, 20 and 25, the numeral 25 being diametrically opposite the Zero mark and at a point most distant from the axis of the disk 9, as the zero mark is nearest the axis of the disk. 7

In the operation of the invention, the inner side of the brake drum is first chalked, after which the brake shoes are assembled therein and expanded against the drum. The drum is' then removed from the brake shoes. The chalk from the brake shoes I.

the drum will have marked the outer side of the linings 4 at such places as have contacted with the chalked inner side of the drum.

If a front brake is to be adjusted, the yoke 24 is fitted on the cylindrical inner part of the spindle 6, as in Fig. 2, with the screw 32 adjusted so that the ball 34 bears against the spindle 6.

The blocks 28 and [9 are now radially adjusted on the rod 23 to approximately their proper positions, and the rod I3 is adjusted in the block l1, and the latter is adjusted on the screw [8 so that the disk 9 is above the lining 4 of one of g The screw 26 is adjusted on the block 28 so as to get a closer adjustment of the block IS. The disk 9 is turned so as to have that portion of its periphery indicated by the zero mark on the side of the disk touch a chalk-ed part of the lining 4, which chalked part was made by the chalked drum. a

The various set screws having been tightened to hold the parts in their adjusted position, and the clamping screw 20 having also been tightened, the gauge yoke is revolved on the spindle to different positions, and the brake shoe I is adjusted so that all portions of the lining 4 will just touch the disk 9 at the zero mark. After this has been accomplished, the periphery of the brake lining will correspond with the inner wall of the drum.

The brake shoe is now adjusted for clearance. The disk 9 is turned so that that portion of its periphery is next to the lining which has the clearance designation corresponding to that desired for that part adjacent to the eccentric 3, the brake shoe being moved inwardly to permit of such turning of the disk 9. Thebrake shoe is then adjusted outwardly until the lining at that point touches the disk 9 at such clearance designation.

The disk 9 is then turned to a position in which the portion indicated by the numeral representing the clearance value desired for that portion of the lining 4 adjacent to the fulcrum of the brake shoe is next the lining, as for example the indication 5, the brake shoe being adjusted so that such portion of the periphery of the disk 9 will touch the lining at such part thereof. By providing the disk 9 with a smooth unbroken circular periphery, as shown, a mi- When the rear brake is to be adjusted, they parts being assembled as shown in Fig. 3 and al- When the rod I3 is in operative position, it will be transverse to the plane of the support rod 23, approximately close to parallelism with the axis of the spindle on which the gauge is mounted,

but it may be at quite an angle to such axis and 4 still be operative.

Various modifications of my invention, within the scope of the appended claims, may be made without departing from the spirit of my invention.

What I claim is:

1. In a gauge of the kind described, the combination with a support adapted to be mounted on an axle spindle, and a member radially adjustable on said support, of a second member radially adjustable on said support independently of said first member, means connecting said members by which said second member is radially adjustable toward or from said first member, supporting means carried by said second member, and a member revoluble on said supporting means on an axis transverse to the line of adjustment of said second member and having peripheral portions adapted to contact with the periphery of a brake shoe and disposed respectively at difierent distances from said axis.

2. In a gauge of the kind described, the combination with a support adapted to be mounted on an axle spindle, and a member radially adjustable thereon, of a second member radially adjustable on said support independently of said first member, means connecting said members by which said second member is radially adjustable toward and from said first member, and means carried by said second member and adapted to contact with the periphery of a brake shoe for designating different clearance values.

3. In a gauge of the kind described, the combination with a support adapted to be mounted on an axle spindle, and a member radially adjustable on said support, of a second member radially adjustable on said support, means connecting said members by which said second member is radially adjustable toward and from said first member, a third member oscillative on said second member on an axis transverse to the axis of said spindle when said support is mounted on the latter, and means carried by said third member and adapted to contact with the periphery of a brake shoe for designating different clearance values.

4. In a gauge of the kind described, the combination with a support having means for embracing an axle spindle, supporting means radially adjustable on said support, and a member adapted to contact with the periphery of a brake shoe and carried by said supporting means, of a member adapted to contact with said spindle and having engagement with said support such that the latter may be tiltably adjusted in a plane parallel with the axis of said spindle when mounted thereon.

5. In a gauge of the kind described, the combination with a support having means adapted to embrace an axle spindle and tiltable on said spindle in a plane parallel to the axis thereof and having a member having a threaded hole extending therethrough in said plane, of a screw fitted in said threaded hole and adapted to have its inner end bear on said spindle and adjustable in said hole so as to hold said support in the position to which said support may be tilted, and a second screw in said plane at one side of said first named screw and extending through said support and adapted to bear on said spindle for tilting said support.

LOREN B. BLACKMAN. 

